ROSACEA. (rose family.) 83 



Var. Illinoensis, Gray. A coarser or larger plant, perhaps » distinct 

 species : the flowers more inclined to be polygamo-diozcious : the villous hairs of the 

 scape and pedicels widely spreading. — The common form in the mountains 

 and extending eastward to the Atlantic States. 



Var. glauea, Watson. Differs from the type in the perfectly smooth and 

 glaucous surface of the leaf. — Bot. King's Exp. 85. In the Wasatch and 

 Uinta Mountains. 



2. P. Vesca, L. Ahenes superficial on the glabrous conical or hemispherical 

 fruiting receptacle (not sunk in pits) : calyx remaining spreading or reflexed : 

 hairs on the scape mostly widely spreading, on the pedicels appressed : leaflets thin, 

 even the upper surface strongly marked by the veins. — Throughout the 

 United States and Arctic America. 



16. POTENTILLA, L. Five-finger. 



Petals 5, obcordate or broadly obovate. Styles lateral or nearly terminal, 

 short, deciduous. Akenes small, turgid, crustaceous. — Herbaceous or rarely 

 woody : flowers cymose, or axillary and solitary. — Watson, Proc. Am. Acad, 

 viii. 549. 



* Styles thickened and glandular toward the base: carpels glabrous, sessile: in- 

 florescence cymose. 

 f- Style attached below the middle of the ovary : disk thickened : stamens 25 to 

 30 : perennial herbs with glandular-villous pubescence and pinnate leaves. 



1. P. arguta, Pursh. Stem erect and stout, 1 to 4 feet high, simple 

 below : radical leaves 7 to 11 foliolate ; leaflets rounded, ovate, or subrhom- 

 boidal, incised or doubly serrate : cyme strict and rather close : calyx densely 

 pubescent : stamens mostly 30. — New Mexico and northward to N. Idaho, thence 

 eastward to the New England States and Canada. 



2. P. glandulosa, Lindl. Resembling the last, but usually more slender 

 and branched, 1 to 2 feet high, and for the most part less pubescent : leaflets 

 more frequently 5 to 9 : cyme panicled, with elongated branches and more slender 

 pedicels : calyx much less tomentose : stamens usually 25. — P. flssa, Nutt. In 

 the mountains, from New Mexico and Colorado northward, and thence west- 

 ward to California and Washington. 



+- +- Style terminal: disk not thickened : flowers small: leaves pinnate or 



ternate. 

 ■h- Annual or biennial: leaflets incisely serrate, not white-tomentose : stamens 5 



io20. 



3. p. Norvegica, L. Erect, stout, J to 2 feet high, at length dichoto- 

 mous above, hirsute : leaves ternate ; leaflets obovate or oblong-lanceolate : cyme 

 leafy and rather loose: calyx large: stamens 15, rarely 20 : akenes rugose, or 

 nearly smooth : receptacle large, oblong. — Throughout N. America, espe- 

 cially northward. 



4. p. rivalis, Nutt. More slender, usually diffusely branched : pubescence 

 softly^villous, sometimes nearly wanting : leaves pinnate, with 2 pairs of closely 

 approximate leaflets, or a single pair and the terminal leaf 3-parted ; upper 

 leaves ternate ; leaflets cuneate-ovate to -lanceolate, coarsely serrate : cymes 

 loose, less leafy: calyx small: petals minute: stamens 10 to 20 : akenes u.sually 



